Cadmium Toxicity Is Regulated by Peroxisome Proliferator-Activated Receptor δ in Human Proximal Tubular Cells

Cadmium Highlights Common and Specific Responses of Two Freshwater Sentinel Species, Dreissena polymorpha and Dreissena rostriformis bugensis

Zebra mussel (ZM), Dreissena polymorpha, commonly used as a sentinel species in freshwater biomonitoring, is now in competition for habitat with quagga mussel (QM), Dreissena rostriformis bugensis. This raises the question of the quagga mussel's use in environmental survey. To better characterise QM response to stress compared with ZM, both species were exposed to cadmium (100 µg·L-1), a classic pollutant, for 7 days under controlled conditions. The gill proteomes were analysed using two-dimensional electrophoresis coupled with mass spectrometry. For ZM, 81 out of 88 proteoforms of variable abundance were identified using mass spectrometry, and for QM, 105 out of 134. Interestingly, the proteomic response amplitude varied drastically, with 5.6% of proteoforms of variable abundance (DAPs) in ZM versus 9.4% in QM. QM also exhibited greater cadmium accumulation. Only 12 common DAPs were observed. Several short proteoforms were detected, suggesting proteolysis. Functional analysis is consistent with the pleiotropic effects of the toxic metal ion cadmium, with alterations in sulphur and glutathione metabolisms, cellular calcium signalling, cytoskeletal dynamics, energy production, chaperone activation, and membrane events with numerous proteins involved in trafficking and endocytosis/exocytosis processes. Beyond common responses, the sister species display distinct reactions, with cellular response to stress being the main category involved in ZM as opposed to calcium and cytoskeleton alterations in QM. Moreover, QM exhibited greater evidence of proteolysis and cell death. Overall, these results suggest that QM has a weaker stress response capacity than ZM.

Gallic Acid Ameliorates Cadmium Effect on Osteogenesis by Activation of Alkaline Phosphatase and Collagen Synthesis

OBJECTIVE

We previously reported that cadmium (Cd) inhibits osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). In addition, gallic acid (GA) improves BMSC differentiation. Here, we aim to study the ability of GA to prevent osteogenic inhibition induced by Cd.

MATERIALS AND METHODS

In this experimental study, BMSCs were extracted and purified from Wistar rats and their viability was determined in the presence of Cd and GA. The results indicated that 1.5 μM Cd and 0.25 μM of GA were appropriate for further investigation. After 20 days in osteogenic medium, matrix production was analysed by alizarin red, calcium content, and alkaline phosphatase (ALP) activity. Osteogenic-related genes and collagen 1A1 (COL1A1) protein expressions were investigated. The preventive effect of GA on oxidative stress and metabolic change induced by Cd was estimated.

RESULTS

GA counteracted the inhibitory effect of Cd on matrix production and significantly (P=0.0001) improved the osteogenic differentiation ability of BMSCs. Also, GA prevented the toxic effect of Cd on osteogenic-related gene expressions and nullified the reducing effect of Cd on COL1Al and ALP activity. A significant reduction (P=0.0001) in malondialdehyde and lactic acid concentration showed that GA counteracted both oxidative stress and metabolic changes caused by Cd.

CONCLUSION

GA prevented the toxic effect of Cd, an environmental pollutant and a factor in osteoporosis.

Upconversion Nanoparticle-Based Cell Membrane-Coated cRGD Peptide Bioorthogonally Labeled Nanoplatform for Glioblastoma Treatment

Glioblastoma is hard to be eradicated partly because of the obstructive blood-brain barrier (BBB) and the dynamic autophagy activities of glioblastoma. Here, hydroxychloroquine (HDX)-loaded yolk-shell upconversion nanoparticle (UCNP)@Zn0.5Cd0.5S nanoparticle coating with the cyclic Arg-Gly-Asp (cRGD)-grafted glioblastoma cell membrane for near-infrared (NIR)-triggered treatment of glioblastoma is prepared for the first time. UCNPs@Zn0.5Cd0.5S (abbreviated as YSN, yolk-shell nanoparticle) under NIR radiation will generate reactive oxygen species for imposing cytotoxicity. HDX, the only available autophagy inhibitor in clinical studies, can enhance cytotoxicity by preventing damaged organelles from being recycled. The cRGD-decorated cell membrane allowed the HDX-loaded nanoparticles to efficiently bypass the BBB and specifically target glioblastoma cells. Exceptional treatment efficacy of the NIR-triggered chemotherapy and photodynamic therapy was achieved in U87 cells and in the mouse glioblastoma model as well. Our results provided proof-of-concept evidence that HDX@YSN@CCM@cRGD could overcome the delivery barriers and achieve targeted treatment of glioblastoma.